Slice top third of each loaf.,Remove bread inside each loaf, leaving about 1/2-inch shell.,Save inside of bread for bread crumbs.,Place lentils in large soup pot with 1 1/2 quarts water. Bring to boil.,Reduce heat and simmer 45 minutes or until tender. Drain lentils, reserving liquid.,Puree lentils in blender, adding enough reserved liquid to make 3 cups of soup.,Return soup to pot; reserve.,Saute onion and garlic in nonstick skillet until onion is tender.,Stir into soup along with spinach, lemon juice and thyme. Season with salt and pepper.,Simmer until spinach wilts and soup is hot.,While soup heats, place bread bowls on baking sheets and heat in 375° oven 5 minutes or until crisp.,Ladle soup into bowls and replace bread tops.,Sprinkle with cheese.,Broil to melt cheese.,Serve promptly.,______